Piper COMANCHE PA-24-180 Service Manual page 643

Trouble
Excessive arcing of
motor brushes
Excessive wear and
arcing of motor
brushes
Binding, worn, or improperly
seated brush or brushes
with excessive side play
Dirty commutator, rough,
pitted, or scored.
Rough or scored com-
mutator
Armature assembly not
concentric
PIPER COMANCHE SERVICE MANUAL
TABLE IX-VII. TROUBLESHOOTING (cont)
Cause
Remedy
Motor fails to operate.
(cont)
Low motor and cranking
speed
Grounded or open field
circuit.
Worn, rough, or improperly
lubricated motor or
st rter gearing.
Test, repair if possible or
replace with a new part.
Disassemble, clean, inspect,
and relubricate, replacing
ball bearings if worn
Same electrical causes as
listed under "Motor
fails to operate".
Same remedies listed for
these troubles.
See information above dealing
with this trouble
Clean as ou. .ed above.
Remove and turn commutator
down on a lathe
Reface commutator
ELECTRICAL SYSTEM
ISSUED: 8/18/72
3 F4